A HaloSat Analysis of the Cygnus Superbubble

TL;DR

This study uses HaloSat X-ray observations to analyze the Cygnus Superbubble, revealing it as a cohesive structure likely originating from a single event, with consistent absorption and temperature across multiple fields.

Contribution

First detailed HaloSat X-ray analysis of the CSB showing its cohesive nature and estimating its physical properties and distance.

Findings

CSB has consistent absorption and temperature across observed fields.

Estimated total thermal energy of the CSB is 4x10^52 erg.

CSB likely located at 1.1-1.4 kpc, similar to Cyg OB1.

Abstract

The Cygnus Superbubble (CSB) is a region of soft X-ray emission approximately 13 degrees wide in the direction of the local spiral arm. Such a large region might be the result of strong stellar winds and supernovae from nearby stellar nurseries, or it could be the result of a single event - a hypernova. HaloSat observed 4 non-overlapping 10 degree diameter fields in the CSB region over the 0.4-7 keV band. The CSB absorption and temperature was found to be consistent over all 4 fields, with a weighted average of 6.1x10^21 cm^-2 and 0.190 keV, respectively. These observations suggest that the CSB is a cohesive object with a singular origin. The total thermal energy for the CSB is estimated at 4x10^52 erg, based upon a shell-like physical model of the CSB. Absorption and distance estimates to Cyg OB associations are examined. The CSB absorption is found to be most consistent with the absorption seen in Cyg OB1, implying that the CSB lies at a similar distance of 1.1-1.4 kpc.